Method of constructing electrodynamic armatures



Mar. 13, 1923. 1,447,993. .A. D. T. LIBBY.

METHOD OF CONSTRUCTING ELECTRODYNAMIC ARMATURES. FILED SEPT. 22,1919.

Paeented Mar. 13, 1923.

llNlTED STATES PATENT oFFIcE.

ALBION D. T. LIBBY, OF EAST ORANGE, NEW JERSEY, ASSIGNGR TO SPLITDORF ELECTRICAL COMPANY, OF NEWARK, NEW JERSEY.

METHOD COIQ'STRUCTING .ELECTRODYNAMIC ARMATURES.

Application filed September 22, 1919.

The method is particularly ariapted for use in the construction of armatures for start ing motors usecl on internal combustion engines, although is to be unsierstoorl thao I do not limit myself to this particular aolaptation of the method herein describedas it may be employed in the construction oi other dynamo electric machines, such as rotors of induction motors anal the like.

the construction of starting motors for automotive vehicles, the armature conoluo tors are of relatively large cross section, as in some cases the current at the instant oi closing the starting switch run as high as 500 or 600 amperes ancl in most cases er;- ceecls amperes during the cranking periocl. Many oi these motor armatures are less than 3" in cliameter an will thus he sat amount of we olelivereol by seen them is enormous for short intervals oi time.

In the construction of a'rmatures for motors of the character above described, a great deal of olifiiculty has been experiencerl in sol ering the heavy armature conductors to the commutator oar risers. The usual construction provides for two of these heavy concluctors being soldereol to one commut tor her and' many times it is founcl thee the conouctor lying in the bottom of the slot in the commutator bar rise'r is not securely soldered to the saicl riser. A load joint of this kind immediately effects the torque of the motor and is a very annoying trouble to fiml because of the fact that after the concluctors are all in place the joint may look perfectly good while when the armature is rotated in the motor field the forces acting on the conductor will move it in the saicl slot of the commutator bar riser ancl the motor will show defective on tests.

Serial No. 325,445.

Sometimes it has happened that the motors away with all soldered joints and thereby reduce the armature resistance to a minimum which means greater current through the armature and an increaserl torque. The method outlined herein'is such that while the conductors are being united the conductor ends are open and visible to the operator so that he can see exactly what kind of a union he has made between the proper condoctor ends.

In the application of Henry Berger, S. N. 1397?.9, filed December 30, 1916, there is shown ancl descriheol a dynamo electric armature in which the end turns of the cor: doctors are bare so that the brushes may he operatecl directly on said conductor encl turns. The present invention is directed to a method of uniting the conductor ends, such as shown in said Berger application, in a speerlie'r and more satisfactory manner than therein shown aml clescribecl.

The method claimed herein will he readily understood by reference to the drawing, wherein- Figure illustrates an armature core with the conductors assemblecl thereon ans placed in a position "to have the open enrls of the conductor joinerl, the welcling transformer and. the welding electrode being shown diagrammatically.

Figure is a top View of Figure i showin the complete conductor encls.

ignre 3 is a view of a spacing member which may be used in the welcling operation and also shows two sets of conoluetors in position 'rherein.

Figure 1- is a partial View of the preferred form of ooncluctors used on the armature shown in Figure 1.

As shown, 1 illustrates the core lamination. having slots either open or elosecl in its periphery and. in which conductors 2 are placed. in the type of armature shown there are two conductors per slot as will be inclicatel in Figure 2. Where the eml turns are brought out the top anal bottom layers are preferably separated by a sheet found that a minimum amount of work is requlredvon an armature of this character when a hairpin type of conductor is used,

- have illustrated that shown and described in Tomlinson Patent #1262873, issuedfipril 16, 1918. Afterthe core has been assembled in a similar manner t that described in said patent and the conductors'placed in; the

- core slots, being insulated from the core in any well known manner, the armature is set into a vessel 4 which'contains some liquid conductor 5, such as mercury, throughthe medium of which all of the bare conductor ends at this end of the core are short cirouited. To the vessel 4 I attach one terminal of a source of welding current, such as an alternating current welding transformer similar to that shown. and described in Patent #1305363, issued June 3, 1919, to

Claude J. Holslag, theother terminal of said source being connected to an electrode 6 preferably metallic and of the same material as the conductors 2. After the open ends of the conductors 2 have been aligned in proper order, I then strike an arc with the electrode 6 between a air of the conductors which are to be joine together, as indicated at 7 in Figure 3. In order to assist in the alignment of the open conductor ends and in the welding operation, I may use a spacing member 8 having slots 9 therein which is adapted to drop over the end of the conductors2 which are in a position to be welded as indicated at A, Figure 3. The complete welding operation is indicated at slot B in Figure 3. llhe complete welded conductor ends are indicated in Figure 2.

While l[ have shown one methodof connecting the source of welding current to the bare conductor ends, it will be understood that any other suitable method of connecting said terminal to the conductors to be welded may be adopted as well as any other type of spacing member for the open ,ends. It is also to be understood that in some cases the autogenous form of welding may be used, such as oXy-acetylene burners, but I prefer to use an electric arc in the manner herein described although I wish it to be under stood that a carbon arc with a separate copper stick may come within the scope of my invention.

While I have shown and described one form of applying my invention to the construction of an electro-dynamic armature,

it will be understood that numerous changes and alterations may be madein the details without departing from the spirit of my inventionand the scope of the appended claims.

Having thus described my invention, what I claim is 1. The method of constructing an electro-dynamic armature which consists in placing on the core thereof but insulated therefrom a series of conductors having bare open end turns at one or both ends of the core, arranging said end turns in spaced relationship and alignment to produce an operative winding when connected, and then welding said end turns together with an open arc in which one of the electrodes consists of said end turns and the other a metallic rod preferably of the same composition dllClJOI', and striking an are between the conductors and the electrode, thereby melting the ends of the conductors and a portion of the electrode together.

In testimony whereof, I afix my signature.

ALBIUN D. T. LIBBY. 

